Combustion tube heater for cooking containers



Dec. 2,

1947. F. w. HOLDERLE El AL COMBUSTION TUBE HEATER FOR CO OKINGCONTAINERS Filed April 16, 1945 2 Sheets- Sheet 1 INVENTORS Dec. 2,1947. F. w. HOLDERLE ET AL 2,431,753

I COMBUSTION TUBE HEATER FOR COOKING CONTAINERS Filed April 16, 1945 2Sheets-Sheet 2' Mair I Patented Dec. 2, 1947 STATES PATENT OFFICE=COMBUSTION TUBE HEATER FOR COOKING CONTAINERS Frederick W. Holderle andCarl L. Holderle, Rochester, N. Y.

Application April 16, 1945, Serial No. 588,680

'11 Claims. 1

"This invention relates to a'cookingapparatus,

with particular reference to the type ofconstruction employed for fryingdoughnuts, potatoes, and the like, including a containerfor a liquidcooking medium such'as'grease or oil in which for decreasing therelativeintensity of the heat below the heatingtubessoas toafford amuchcooler body of'liquidc below the tubes, at the same time increasing theheating efficiency of the fuel by diverting .a maximum amount of heatupwardly into contact with the top walls of the heating tubes, andpermitting a minimum amount of heat to becarried off through the exhaustflue.

Still anothernbject of'theinvention is to afford a simple, practical,and economical construction that functions to cause cold air fromaroundor below the burner totravelthrough the lower part of the heatingtubenwhile the flame and products ofcombustion travel through the upperpart of the tube, andare diverted toward the top wall of the tube astheytpass through to the exhaust fiue.

An additional purpose is to affordan improved form of heating tubewhereby the area of heating surface at the top of the tube is increasedin conjunction with means for diverting the hot products ofcombustion-toward the greater heating surface atthe top of the tube, as-.a consequence of which the increased heating surface acts to heat thecooking liquid to a maximum degree.

To these andother'ends, the invention consists in the construction andarrangement of parts that will'appear clearly fro the followingdescription when 'read'in'conjunction with the accompanying drawings,the novel features being pointed out in the claims followingthespecification.

In the drawings:

Fig. 1 is a view infront' elevation, partially in section, of a cookingapparatus constructed in accordance with apreferred embodiment of theinvention;

Fig.2 isaplan view;

"2 Fig. 3 is a verticalsectionahview'taken centrally of Fig. 1,withtparts in elevation;

Fig, 4 is a longitudinal'vertical sectional View taken centrally of oneof the heating tubes;

Fig. 5 is a horizontal sectional view taken centrally of Fig.4, showingthe partition in elevatic-n;

Fig. 6 is aview in front end elevation of the heating tube andlpartitionillustrated in Figs. 4 and 5, and I Fig. '7 is a transverse'verticalsectionalview on line 'l"| of Fig, 4, looking in the directionindivcated.

Referring'more/particularly to the drawings in which like referencenumerals refer'to the same parts throughout the several views, Idesignates the main wall or casing of the cooking apparatus within whichis supported a container or receptacle 2 for-thecooking liquid such asrease or oil, it being understood'ithat the articles to be cooked aresubmerged within the liquid in the container "2 while supported within asuitable basket which. constitutes nopart of the invention and is notshown.

The liqu dcontainer'ilis provided with inclined bottom walls 3Laffordinga sediment chamber and terminating in anoutlet controlled by a suitabledrain valve '4, while "5 designates heating tubes extending throughthewalls of the liquid container 2 from front to back thereof andlocated somewhatvabove the bottom of the container 2 and below thenormal level of liquid in the container, so that when the'articles to becooked are positioned within the liquid in the container above theheating tubes "5, they'ca'n'be cooked quickly at a'temperature that issusceptible of close, accuratecontrol. The heating tubes at their rearends connect with an exhaust flue B through which the smokeand'burnedproducts are carried off.

Heat is supplied-to'the'heating tubes by' means of conventional gasburners I, as usual in this type of construction, the burners I beingsupplied with gas through connections'from a' gas supply pipe 8, towhich gasis fed from an inlet pipe 9, after passing through "atemperature controlled valve Ill. The valve! isgoverned bya thermostatIl suitably mounted within thecontainer 2 and preferably locatedparallel to the heating tubes in slightly spaced relation thereto and ona level with or slightly'below the top walls of the heating tubes sothat as the temperature of the cooking liquid rises or falls, it closesor opens the valve I0 respectively, to control the'supply of gas to'theburners,=the 'flames ofwhich'are directed into the heating tubes. Thethermostatic valve H! can be set to any desired temperature and willmaintain the temperature of the cooking liquid very nearly constant withbut slight variations owing to the heating efliciency and extremesensitivity of the heating tubes, as will be described presently.

Each heating tube is constructed as shown in Figs. 4 to 7 inclusive, andsince they are identical, it will be necesary to describe in detail onlyone of them. In order to increase the efliciency and heating surface ofthe tube and to increase the relative intensity of the heat generated inthe liquid above the tube while maintaining a relatively cooler area inthe liquid below, each tube is provided in its top wall with transversecorrugations l2, see Figs. 4 and 7, the top surface of each corrugationbeing convexly curved transversely, as shown in Fig. '7, so that anyparticles of food matter falling thereon will not be held but willreadily fall off and be carried downwardly into the sediment chamber atthe bottom of the container 2. The bottoms of the corrugations I2 areconvexly curved to nearly the same extent as the outer periphery of theheating tube, thus avoiding any flat surfaces on which food particlesmight lodge and thereby reduce the heating efficiency of the apparatus.

In order to obtain a maximum effect from any given amount of heatgenerated by a burner, it is desirable to divert the flame andcombustion products toward the top wall of the heating tube and thetransverse corrugations l2, while causing the cold air around and belowthe burner to travel through the heating tube at the bottom thereof. Inorder to accomplish this, there is provided a generally horizontalpartition extending longitudinall through the heating tube and dividingthe tube into upper and lower chambers forming passages through whichthe combustion products and cold air respectively travel.

In the construction shown, the partition is designated at IS with itsfront end resting at points near the bottom of the heating tube, and itsrear end slightly elevated to give an upward inclination to thepartition from front to rear. This is accomplished by providing the rearend of the partition with a depending supporting wall M, the bottom edgeof which conforms to and rests on the bottom of the heating tube, whileI 5 is a central opening in the wall through which the cold air passesoutwardly to the flue.

The front end of the partition 13 has side portions [6 that engage andrest on the adjacent surface of the heating tube, while the centralportion of the partition is curved upwardly as shown at IT, to afford anenlarged throat providing a cold air inlet which facilitates entrance ofcold air to the passage underneath the partition, whence it movesrearwardly and through opening l5, while the flame, hot gases, andcombustion products travel rearwardly above the partition l3 and arediverted toward the top of the heating tube into contact with thecorrugated portions and the portions of the top wall of the tube betweenthe corrugations l2.

In order to insure entrance of the gas flame and hot products above thepartition l3, and entrance of cold air beneath the partition, eachburner 1 is arranged slightly above the top of the throat H, or abovethe front end of the partition H, as shown in Fig. 4. It is desirable toretard travel of the hot products of combustion through the heatingtubes so as to obtain a maximum heating effect on the top wall of theheating tube,

and to attain this end, the partition I3 is provided with bafiles ordeflectors spaced endwise from each other and preferably inclinedupwardly, as shown at [8, I9 and 20. These bafiies may consist of metalplates bent to the desired shape to afford base portions welded orotherwise attached to the partition, the baffles extending laterallyacross the partition and approximately as wide as the Partition, asindicated at Fig. 5.

The battle l9 preferably extends a somewhat greater distance from thepartition than baflle I8 in order to divert a maximum volume of thecombustion products upwardly at the center of the heating tube while theslightly reduced height of the first baffle l8 permits the flame of theburner to project well into the tube and toward the top wall thereof,The partition l3 with its baffles may rest loosely in the heating tubeor may be fastened therein if preferred, and has outwardly curving sideedges as shown in Fig. 5 so that when positioned in the heating tube inthe desired upwardly inclined position, the side edges of the partitionengage and are in substantial contact with the adjacent surfaces of theheating tube, so that there is no space or opening between the edges ofthe partition and the adjacent surfaces of the heating tube, and theupper chamber is effectively separated from the lower chamber.

In operation, the jet of flame from the gas burner enters the front endof the heating tube and is diverted upwardly over the first baffle [8toward the top wall of the heating tube and corrugations l2, while thecold air from around and under the burner enters under the throat H. Thehot products of combustion passing over baflie 58 are diverted furtherupwardly into contact with the top wall of the heating tube and againstthe transverse corrugations i2 by the intermediate bafiie I9, andcontinue on over baffle 253 and outwardly to the exhaust flue 6, all thehot products of combustion traveling from the front end of the heatingtube to the rear end thereof through the passage above the partition,while any cold air passes under the throat I1 and travels rearwardlythrough the passage beneath the partition, thence through opening I5 inthe supporting wall M at the back end of the partition and to the flueoutlet.

With this arrangement, the cooking liquid above the heating tubes iskept intensely hot while the liquid below the heating tube is relativelycooler and particles of food falling into the sediment zone will not beburned but can be drawn off through the discharge outlet at suitableintervals. With the construction described, considerably greater heatingefficiency is obtained because less heat is permitted to pass to theexhaust flue 6 and more heat is diverted to the top wall of the heatingtube. As a result of this arrangement and the corrugations 12, thecooking liquid is heated from a cold temperature to the required cookingtemperature in much less time than with prior structures for the samepurpose. The structure permits closer and more accurate control andenables a more nearly constant cooking temperature, due to the fact thatthe thermostat is located in the portion of the cooking liquid adjacentto the top walls of the heating tubes where the heat is most intense,whereas the cooking liquid below the cooking tubes is relatively cooler.The temperature changes Where the thermostat is located are quicker thanwith prior structures, consequently there is less lag between theopening and closing operations of the controlling valve, and the tem--eaten- :perature of the liquid-:can be-maintairred-more mea'rly constantfor :any given settingofithetheramostati'c valve.

while the'iinvention rhas' been ldescribed with srelation' to aparticular embodiment; it is 'not re- :zstricted to ithe details shown,and 'thisapplica 7 tion isiintended to cover su'ch changesunmodifications as may :come "within the purposes of the improvement. orthe so one ofthe "following: claims.

a1=cooking .:apparatus, (the scom'bina'tion with a :container :for aliquid hooking nne'dium, sand "a .heating ltube :exten'ding horizontallylthroughfsaid containerlatafpoint above'lthe:bot- :tom of the: container:and'zbelowithe normalilliq- --uid."1evel therein, for .a generallyhorizontal pa'rdition extending longitudinally through-the heatiingitubewith its side edges'substantially in coniitact withthe side walls of thetube affording upjpfi l' and ilower passages through which -'-thecomllbustioniproducts and cold air respectively travel, and a burner infrOnt of -the heating tube loc'cated above the front end'of-thepartition.

l2; Ina'eooking'apparatus, the ccrnbination with a container for aliquid cookin'g'mediu'm, and a heating tube extending horizontallythrough said container at:avpoint above' the bottom of the containeran'd below the normal liquid level therein, of a generally horizontalpartition extending longitudinally through the '*heating tube with-.-.curved* side edges substantially incontact with the side walls ofthe tube, :said partition being inclined upwardly from a point near thebottom of the tube atits forward end toward the rear end thereofaffording upper and lower pas- -.sages:through whichthe combustionproducts-land 'c0ldai1"respectively travel, anda burnerlini f-ront'of"the'heating tube located above the frohtend tof the partition.

3. In a cooking apparatus; the combination with -a'container fora liquideooking:medium,.and a heating tube" extendinghorizontally through saidcontainer at a point above the bottom of the container and below thenormal liquid level therein, of a generally horizontal-partitionextending longitudinally-through the'heating tube with its side edgessubstantially in contact with the side walls of the tube affording upperand lower passages through which the combustion products and cold airrespectively travel, a plurality of baffies extending upwardly from thepartition toward the top of the heating tube, said baffles being spacedfrom the top of the tube and from each other, and a burner in front ofthe heating tube located above the front end of said parti' tion.

4. In a cooking apparatus, the combination with a container for a liquidcooking medium, and a heating tube extending horizontally through saidcontainer at a point above the bottom of the container and below thenormal liquid level therein, of a generally horizontal partitionextending longitudinally through the heating tube with curved side edgessubstantially in contact with the side walls of the tube, said partitionbeing inclined upwardly from a point near the bottom of the tube at itsforward end toward the rear end thereof affording upper and lowerpassages through which the combustion products and cold air respectivelytravel, a plurality of bafiies extending upwardly from the partitiontoward the top of the heating tube, said baffles being spaced from thetop of the tube and from each other, and a burner in front of theheating tube located above the front end of said partition.

26 5. Ina'cookingaapparatus,"the comblnation with a cont-ainer for' aliquid cooking medium,.iand 5a heating -tu-be extending "horizontally'through:.said 'container at a point above the bottom of the containerand below the normal liquid level there- -in, of=a generally horizontalpartition extending longitudinally through the :heating tube with curvedside :edges substantially .in contact-with the "side'- walls or: thetube, said partition being inclined upwar'dly' from a point near 'the.bottom :of-flthe? tubeiat its forward end toward .the mean endithereofiiafiording upper and lower. pass ages through which: thecombustion "products -and".coldiair respectivelyltravel, theforward'en'd of saidi partition having .acentrallyzarrangdaupiwardlyzcurved throatiforming a-cold' air .inlet, taplurality :ofxbaffies extending upwardly-fromathe rpartition-towardithetop of the'heating tube; said ,zbafilessheingsspaced from the top of thetube and from eachzother, r and a" burner in front 'of 'the :rh'eatin'gtube located above "said throat 'in the f'iflul'llffel'l dofsaidpartition.

=-"6.TrIn:,-a cooking apparatus, the combination "with-acontainer for a.liquidcooking medium, and a heating tube extending horizontally through=said containeratarpoint above the bottom of the icontainer, and below:the normal liquidlevel there- :in, r=.of a generally :horizontalpartition extending elon'gitudinally through the heating tube withcurvedssideedges substantially in contact with :the :"sidewalls of .the'tube, said partition':having lLits-forwardxend in close proximity to:the bottom -ofthe}heating tube'and its reartend spaced .:a greater"distance above the bottom of..the tube, 'the forwardiend of saidpartition having a. centrally arranged upwardly curved throat forminga'i coldaair: inlet and the rear end of the partition rha-ving a;depending supporting wall with an opening therein affording a coldair'outlet;a'plura1ity of rearwardly' inclined baffles. extendingupwardly *from thepartitionxtowardzthe top of the heating tube; saidbafiles being spaced from the top of the :tube andifromteach other, anda burner .in front rofthe heating tube'xlocated above said throattinthefront e'nd'of saidpartition.

-7.:rIn';a cooking :apparatus, the combination with a container foraliquid cooking medium an'd a heating tube extending horizontallythrough said container at a point above the bottom of the container andbelow the normal liquid level therein, said heating tube having a seriesof transverse corrugations in its top wall, the outer surfaces of saidcorrugations being convexly curved transversely, of a generallyhorizontal partition extending longitudinally through the heating tubewith its side edges substantially in contact with the side walls of thetube affording upper and lower passages through which the combustionproducts and cold air respectively travel, and a burner in front of theheating tube located above the front end of the partition.

8. In a cooking apparatus, the combination with a container for a liquidcooking medium, and a heating tube extending horizontally through saidcontainer at a point above the bottom of the container and below thenormal liquid level therein, said heating tube having a series oftransverse corrugations in its top wall, the outer surfaces of saidcorrugations being convexly curved transversely, of a generallyhorizontal partition extending longitudinally through the heating tubewith its side edges substantially in contact with the side walls of thetube, said partition being inclined upwardly from a point near thebottom of the tube at its forward end toward the rear end thereofaffording upper and lower passages through which the combustion productsand cold air respectively travel, and a burner in front of the heatingtube located above the front end of the partition.

9. In a cooking apparatus, the combination with a container for a liquidcooking medium, and a heating tube extending horizontally through saidcontainer at a point above the bottom of the container and below thenormal liquid level therein, said heating tube having a series oftransverse corrugations in its top wall, the outer surfaces of saidcorrugations being convexly curved transversely, of a generallyhorizontal partition extending longitudinally through the heating tubewith its side edges substantially in contact with the side walls of thetube affording upper and lower passages through which the combustionproducts and cold air respectively travel, a plurality of bafilesextending upwardly from the partition toward the top of the heatingtube, said bafiies being spaced from the top of the tube and from eachother, and a burner in front of the heating tube located above the frontend of the partition.

10. In a cooking apparatus, the combination with a container for aliquid cooking medium, and a heating tube extending horizontally throughsaid container at a point above the bottom of the container and belowthe normal liquid level therein, said heating tube having a series oftransverse corrugations in its top wall, the outer surfaces of saidcorrugations being convexly curved transversely, of a generallyhorizontal partition extending longitudinally through the heating tubewith curved side edges substantially in contact with the side walls ofthe tube, said partition being inclined upwardly from a point near thebottom of the tube at its forward end toward the rear end thereofaffording upper and lower passages through which the combustion productsand cold air respectively travel, a plurality of baiiies extendingupwardly from the partition toward the top of the heating tube, saidbaifles being spaced from the top of the tube and from each other, and aburner in front of the heating tube located above the front end of thepartition.

11. In a cooking apparatus, the combination with a container for aliquid cooking medium, and a heating tube extending horizontally throughsaid container at a point above the bottom of the container and belowthe normal liquid level therein, said heating tube having a series oftransverse corrugations in its top wall, the outer surfaces of saidcorrugations being convexly curved transversely, of a generallyhorizontal partition extending longitudinally through the heating tubwith curved side edges substantially in contact with the side walls ofthe tube, said partition being inclined upwardly from a point near thebottom of the tube at its forward end toward the rear end thereofaffording upper and lower passages through which the combustion productsand cold air respectively travel, a plurality of bafiles extendingupwardly from the partition toward the top of the heating tube, saidbaffles being spaced from the top of the tube and from each other, theforward end of said partition having a centrally arranged upwardlycurved throat forming a cold air inlet, and a burner in front of theheating tube located above said cold air inlet.

FREDERICK W. HOLDERLE. CARL L. HOLDERLE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,315,853 Nordling et al Sept. 9,1919 1,630,309 Pitman May 31, 1927 1,923,639 ODowd Aug. 22, 19331,931,120 Shroyer Oct. 17, 1933 1,991,788 Cartter Feb. 19, 19352,124,186 Childs July 19, 1938 FOREIGN PATENTS Number Country Date655,948 Germany Jan. 26, 1938

